Permanent barriers. The biggest challenge we've heard, or one of the biggest push-backs, is the canal barges in the Chicago area. To be honest with you, I'm not an expert in this area at all, but I don't see why you can't have roll-on, roll-off barges coming up to this barrier in between—save jobs and save the barging industry—and create this concrete or land barrier that will separate in real terms the two bodies of water, as they once were.
On April 30th, 2012. See this statement in context.